Buried beneath a tiny island, just off Nova Scotia, lies the most famous pirate treasure ever known. Or at least it might be buried there. But despite hundreds of years of searching, no one has yet found any of it. The story begins in 1795, when a young man called Daniel McGinnis was exploring the south end of Oak Island, and came across a clearing in the forest, in the centre of which was a small depression in the ground. Hanging from a tree above was a tackle block, used for a pulley system.

Daniel and two of his friends began to excavate, and found first a layer of flagstones, then several layers of logs, each about ten feet deeper than the last. Eventually the men gave up, but several years later another excavation took place. This time, as well as finding charcoal and coconut fibres deep underground, a large stone was uncovered about ninety feet beneath the surface, with strange symbols carved into it. The symbols were translated as: "Forty feet below, two million pounds lie buried".

It is more than two hundred years since that discovery was made, and many more excavations have been made during that time. The hundreds of treasure hunters who have made their way to Oak Island have even included Franklin D Roosevelt – later the president of the United States.

Theories of what might lie at the bottom of the 'money pit' abound. The lost treasure of Captain Kidd or Blackbeard; Marie Antoinette's jewels; the Holy Grail; Masonic secrets; proof of who really wrote Shakespeare's plays: all have been suggested. So too has the possibility that it might just be a natural sink hole, adorned with rather too many imaginative stories.